This abstract element defines an equivalence class over the
elements which occur freely at the top level of schemas.
These are: datatype, type, element, attributeGroup, group, notation
All of their types are based on the "annotated" type
by extension.A utility type, not for public useelement@nameattribute@namecomplexType|simpleType@namegroup@nameattributeGroup@namenotation@name.//key|.//unique|.//keyref@nameallows 'unbounded', so integer won't doWill be restricted to required or forbiddenA utility type, not for public useA utility type, not for public use#all or (possibly empty) subset of {equivClass,
extension, restriction}A utility type, not for public use#all or (possibly empty) subset of {extension,
restriction}A utility type, not for public use##any | ##other | list of {uri, ##targetNamespace, ##local}A utility type, not for public useAn XPath expressionA utility type, not for public useA VERY permissive definition,
probably not even right
A public identifier, per ISO 8879A utility type, not for public use